DOCSLIB.ORG

What Is Radiation? Introduction Different Types of (Dose) of Radiation

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
What Is Radiation? Introduction Different Types of (Dose) of Radiation What is Radiation? Introduction Different Types of (dose) of radiation. A millirem is one Radiation one-thousandth of a rem. Radiation is energy in the form of waves or particles. Although Alpha particles travel only a few inches The average individual receives radiation is around us every day, in the air and lose energy almost as approximately 300 millirem of radiation you cannot see, hear, or smell it. soon as they encounter an obstacle such per year from natural background Radiation is detected by measuring as a sheet of paper or the outer layer sources. The legal radiation exposure limit for an 18-year old male, whose the activity of the energy released of a person’s skin. Alpha particles are profession allows or permits exposure, is as it decays. It comes from natural hazardous only when they are inhaled or 5,000 millirem per year; and 500 millirem and man-made sources as unstable ingested. for a woman during pregnancy. atoms decay to form more stable Beta particles can travel in the air for a atoms. few feet and can be stopped by a sheet of aluminum foil or glass. Beta particles Sources of Radiation can damage skin and eyes, but are most hazardous when swallowed or ingested. Radiation may be found everywhere, be it naturally occurring or from man-made Gamma rays are waves of pure energy sources. Natural sources of radiation and are similar to x-rays. They travel at include: the speed of light through air or open spaces. Concrete, lead, or steel must be • The human body. About 31 millirem used to block gamma rays. Gamma rays of the average person’s total are an external hazard. exposure emanates from within the body itself. Potassium-40 and other Neutrons are small particles that have radioactive isotopes found in the no electrical charge. They are released air, water and soil are incorporated during nuclear fission and can travel long into the food we eat, then into body distances in the air. Water or concrete tissue. are the best shielding against neutrons. Like gamma rays, neutrons can present • Terrestrial sources. Radon is the an external hazard. largest source of radiation exposure (~230 millirem/per year) in the United States. In addition, rocks, soil and Measurements of Radiation building materials derived from the earth’s crust, like granite, account for Radiation is measured in different ways: an additional 19 millirem per year. • Rad (radiation absorbed dose) is the • Cosmic rays. The average person amount of energy actually absorbed receives about 30 millirem per year by human tissue. of their total exposure from cosmic • Roentgen describes the amount radiation from outer space. Cosmic of radiation energy, in the form of radiation increases with altitude, gamma or x-rays, in the air. roughly doubling every 6,000 feet. • Rem (Roentgen equivalent man) measures the biological damage Medical Cosmic Man-made radiation 298 mrem 30 mrem sources include: • Medical procedures such as x-rays, nuclear medicine, and CAT scans Terrestrial Consumer Products (from Earth) expose the average 12 mrem American to another 19 mrem 29 millirem. • Consumer products. The average American receives Radon Human Body 230 mrem about 12 millirem of 31 mrem their total exposure to radiation from consumer products. Exposure comes from smoke such effects increases with dose, but detectors, building materials, and the severity does not. Cancer is the television sets. Lawn fertilizer only observed clinical manifestation of can also expose an individual to radiation-induced stochastic effects. radiation. Fertilizer contains trace There is a substantial delay between the amounts of potassium-40, a naturally time of exposure and the appearance of radioactive material. the cancer. Stochastic radiation can also damage the germ cells (ova and sperm) Less than one percent of total exposure- to produce hereditary effects. comes from a variety of other sources, including fallout from past testing of nuclear weapons, and from the generation of electricity in nuclear, coal- Protection fired, and geothermal power plants. To protect your self from radiation, there are three basic concepts to keep in mind: time, distance, and shielding. The Radiation’s Effects on amount of radiation exposure is directly Humans related to the amount of time spent near the source of radiation, the distance The nature and extent of damage caused from the radiation, and the shielding by ionizing radiation depends on the between you and the source of radiation. amount of exposure, the frequency of The less time spent near the source, at exposure, and the penetrating power of the greatest distance, with the greatest For more information, contact: the radiation to which an individual is shield will result in the least exposure. U.S. Department of Energy exposed. There are two main types of National Nuclear Security Administration Nevada Field Office radiation effects on humans: Office of Public Affairs Deterministic radiation occurs at P.O. Box 98518 the cellular level. Effects are usually Las Vegas, NV 89193-8518 manifested soon after exposure. The severity of the effect increases with dose. Phone: 702.295.3521 Examples include radiation skin burning, Fax: 702.295.0154 blood count effects, and cataracts. Email: [email protected] In contrast, stochastic radiation effects www.nnss.gov are caused by more subtle radiation- induced cellular changes (usually DNA mutations). The probability of DOE/NV - -1043 April 2017.
Load more

Recommended publications
  • Absorbed Dose in Radioactive Media Outline Introduction Radiation Equilibrium Charged-Particle Equilibrium Limiting Cases
    Outline • General dose calculation considerations, Absorbed Dose in Radioactive absorbed fraction Media • Radioactive disintegration processes and associated dose deposition – Alpha disintegration Chapter 5 – Beta disintegration – Electron-capture transitions F.A. Attix, Introduction to Radiological – Internal conversion Physics and Radiation Dosimetry • Summary Introduction Radiation equilibrium • We are interested in calculating the absorbed dose in a. The atomic composition radioactive media, applicable to cases of of the medium is – Dose within a radioactive organ homogeneous – Dose in one organ due to radioactive source in another b. The density of the organ medium is • If conditions of CPE or RE are satisfied, dose homogeneous c. The radioactive source calculation is straightforward is uniformly distributed • Intermediate situation is more difficult but can be d. No external electric or handled at least in approximations magnetic fields are present Charged-particle equilibrium Limiting cases • Emitted radiation typically includes both • Each charged particle of a given type and photons (longer range) and charged energy leaving the volume is replaced by an particles (shorter range) identical particle of the same energy entering • Assume the conditions for RE are satisfied the volume • Consider two • Existence of RE is sufficient condition for CPE limited cases based • Even if RE does not exist CPE may still exist on the size of the (for a very large or a very small volume) radioactive object 1 Limiting cases: small object Limiting
    [Show full text]
  • Development of Chemical Dosimeters Development Of
    SUDANSUDAN ACADEMYAGADEMY OFOF SCIENCES(SAS)SGIENGES(SAS) ATOMICATOMIC ENERGYEhTERGYRESEARCHESRESEARCHES COORDINATIONCOORDII\rATI ON COUNCILCOUNCIL - Development of Chemical Dosimeters A dissertation Submitted in a partial Fulfillment of the Requirement forfbr Diploma Degree in Nuclear Science (Chemistry) By FareedFadl Alla MersaniMergani SupervisorDr K.S.Adam MurchMarch 2006 J - - - CONTENTS Subject Page -I - DedicationDedication........ ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... I Acknowledgement ... '" ... ... ... ... ... ... '" ... ... ... ... '" ... '" ....... .. 11II Abstract ... ... ... '" ... ... ... '" ... ... ... ... -..... ... ... ... ... ... ..... III -I Ch-lch-1 DosimetryDosimefry - 1-1t-l IntroductionLntroduction . 1I - 1-2t-2 Principle of Dosimetry '" '" . 2 1-3l-3 DosimetryDosimefiySystems . 3J 1-3-1l-3-l primary standard dosimeters '" . 4 - 1-3-2l-3-Z Reference standard dosimeters ... .. " . 4 1-3-3L-3-3 Transfer standard dosimeters ... ... '" . 4 1-3-4t-3-4 Routine dosimeters . 5 1-4I-4 Measurement of absorbed dose . 6 1-5l-5 Calibration of DosimetryDosimetrvsystemsvstem '" . 6 1-6l-6 Transit dose effects . 8 Ch-2ch-2 Requirements of chemical dosimeters 2-12-l Introduction ... ... ... .............................................. 111l 2-2 Developing of chemical dosimeters ... ... .. ....... ... .. ..... 12t2 2-3 Classification of Dosimetry methods.methods .......................... 14l4 2-4 RequirementsRequiremsnts of ideal chemical dosimeters ,. ... 15 2-5 Types of chemical system .
    [Show full text]
  • The International Commission on Radiological Protection: Historical Overview
    Topical report The International Commission on Radiological Protection: Historical overview The ICRP is revising its basic recommendations by Dr H. Smith Within a few weeks of Roentgen's discovery of gamma rays; 1.5 roentgen per working week for radia- X-rays, the potential of the technique for diagnosing tion, affecting only superficial tissues; and 0.03 roentgen fractures became apparent, but acute adverse effects per working week for neutrons. (such as hair loss, erythema, and dermatitis) made hospital personnel aware of the need to avoid over- Recommendations in the 1950s exposure. Similar undesirable acute effects were By then, it was accepted that the roentgen was reported shortly after the discovery of radium and its inappropriate as a measure of exposure. In 1953, the medical applications. Notwithstanding these observa- ICRU recommended that limits of exposure should be tions, protection of staff exposed to X-rays and gamma based on consideration of the energy absorbed in tissues rays from radium was poorly co-ordinated. and introduced the rad (radiation absorbed dose) as a The British X-ray and Radium Protection Committee unit of absorbed dose (that is, energy imparted by radia- and the American Roentgen Ray Society proposed tion to a unit mass of tissue). In 1954, the ICRP general radiation protection recommendations in the introduced the rem (roentgen equivalent man) as a unit early 1920s. In 1925, at the First International Congress of absorbed dose weighted for the way different types of of Radiology, the need for quantifying exposure was radiation distribute energy in tissue (called the dose recognized. As a result, in 1928 the roentgen was equivalent in 1966).
    [Show full text]
  • Chapter 2 Radiation Safety Manual Revision 1 Principles of Radiation Safety 6/1/2018
    The University of Georgia Chapter 2 Radiation Safety Manual Revision 1 Principles of Radiation Safety 6/1/2018 CHAPTER 2 PRINCIPLES OF RADIATION SAFETY 1.0 UNITS OF RADIATION DOSE 1.1 Historical Units In 1896, x-rays were discovered by Wilhelm Roentgen. The Roentgen is unit of measurement for the exposure of x-rays and gamma rays. It is defined as the electric charge freed by such radiation in a specified volume of air divided by the mass of that air. Radioactivity was discovered by Henri Becquerel. Radioactivity refers to the amount of radiation released when an element spontaneously emits energy as a result of the decay of its unstable atoms. The Becquerel is a unit used to measure radioactivity, and stands for 1 disintegration per second. The Curie is a unit of radioactivity equal to 3.7 X 1010 disintegrations per second and was first used, but being such a large unit was replaced by the Becquerel. The Curie is named for Pierre Curie, Marie Curie’s husband and co- discoverer of radium. After his accidental death, she continued their work. For some time, no one realized that radiation could cause harmful effects. It was recognized very soon that x-rays could be used in medical diagnosis, and early radiologists received large doses of radiation. Many of these radiologists later suffered severe injuries due to overexposure (radiation effects may appear years after exposure). The first unit of dose was the erythema dose. This was the amount of x-radiation which would barely cause reddening of the skin. It was not a very satisfactory unit of dose, but indicates the early recognition by some scientists that radiation exposure can be harmful and should be limited.
    [Show full text]
  • Radiation Glossary
    Radiation Glossary Activity The rate of disintegration (transformation) or decay of radioactive material. The units of activity are Curie (Ci) and the Becquerel (Bq). Agreement State Any state with which the U.S. Nuclear Regulatory Commission has entered into an effective agreement under subsection 274b. of the Atomic Energy Act of 1954, as amended. Under the agreement, the state regulates the use of by-product, source, and small quantities of special nuclear material within said state. Airborne Radioactive Material Radioactive material dispersed in the air in the form of dusts, fumes, particulates, mists, vapors, or gases. ALARA Acronym for "As Low As Reasonably Achievable". Making every reasonable effort to maintain exposures to ionizing radiation as far below the dose limits as practical, consistent with the purpose for which the licensed activity is undertaken. It takes into account the state of technology, the economics of improvements in relation to state of technology, the economics of improvements in relation to benefits to the public health and safety, societal and socioeconomic considerations, and in relation to utilization of radioactive materials and licensed materials in the public interest. Alpha Particle A positively charged particle ejected spontaneously from the nuclei of some radioactive elements. It is identical to a helium nucleus, with a mass number of 4 and a charge of +2. Annual Limit on Intake (ALI) Annual intake of a given radionuclide by "Reference Man" which would result in either a committed effective dose equivalent of 5 rems or a committed dose equivalent of 50 rems to an organ or tissue. Attenuation The process by which radiation is reduced in intensity when passing through some material.
    [Show full text]
  • ACUTE RADIATION SYNDROME: Diagnosis and Treatment
    ACUTE RADIATION SYNDROME: Diagnosis and Treatment Badria Al Hatali, MD Medical Toxicologist Department of Environmental and Occupational Health MOH - Oman Objectives Provide a review of radiation basics and acute radiation sickness Discuss diagnostic tools and triage tools for Acute Radiation Syndromes Discuss management of Acute Radiation Syndromes Energy traveling over a distance as Waves Particles • Gamma rays • Alpha • X-rays • Beta • Radio waves • neurons Non-ionizing vs Ionizing Radiation • High energy • Low energy • Removes orbital electrons • Does not remove orbital from atoms > DNA electrons from atom damage Radioactive Decay Process to Remove excess energy from atomic nuclei Nuclei emit rays or particles to decrease nuclear energy Radioactive materials have unstable nuclei with excess energy Ionizing Radiation Dose • Radiation absorb dose (RAD): the amount of energy absorbed by the body. 1 cGy = 0.01 J/kg (USA) • Gray (Gy): expressed as absorbed energy per unit mass of tissue. 100 rad =100 cGy =1 J/kg (SI) • Roentgen Equivalent Man (REM) relates the absorbed dose in human tissue to the effective biological damage of the radiation (USA) • Sievert (Sv): the absorbed dose in human tissue to the effective biological damage of the radiation (SI) Radioactivity Biological And Effective Half-lives Biological half-life is the time to remove half of radioactive element from body Effective half-life is the combined effect of radioactive decay & biological elimination Effective half-life is always shorter than either physical or biological half-lives Biological Effects of Ionizing Radiation Direct damage Chromosome Other biochemical E.g. alpha and beta particles Indirect damage Chemical changes due to radiolysis of water in cell E.g.
    [Show full text]
  • Emergency and Combat First Aid» Module № 1 Emergency and Combat First Aid Topic 7 Means of Mass Destruction
    Ministry of Health of Ukraine Ukrainian Medical stomatological Academy It is ratified On meeting department Of accident aid and military medicine «___»_____________20 __y. Protocol №_____ Manager of department DMSc ., assistant professor __________К.Shepitko METHODICAL INSTRUCTION FOR INDEPENDENT WORK OF STUDENTS DURING PREPARATIONS FOR THE PRACTICAL LESSON Educational discipline «Emergency and Combat First Aid» Module № 1 Emergency and Combat First Aid Topic 7 Means of Mass Destruction. First Aid. Weapons of mass destructions. Lesson 10 Radiations chemical accidents .First Aid Сourse ІІ Foreing students training dentistry Faculty Training of specialists of the second (master) level of higher of education (название уровня высшего образования) Areas of knowledge _______ 22 «Health protection»_________ (шифр и название области знаний) Specialty ________222 «Medicine», 221 «Stomatology»________________ (код и наименование специальности) Poltava 2019 The relevance of the topic: Military action in modern warfare will be carried out with high activity and limit tension. They cause great losses in the army and among the population, the destruction of potentially dangerous objects, energy centers, waterworks, the formation of large zones of destruction, fires and floods. The main form of countering in the war, is armed struggle - the organized use of armed forces and weapons to achieve specific political and military objectives, a combination of military actions of varying scales. To conventional weapons, the application of which may cause losses among the population are missiles and aerial munitions, including precision munitions volumetric detonation of cluster and incendiary. Have the greatest efficiency high precision conventional weapons, which provide automatic detection and reliable destruction of targets and enemy targets with a single shot (trigger).
    [Show full text]
  • 11. Dosimetry Fundamentals
    Outline • Introduction Dosimetry Fundamentals • Dosimeter model • Interpretation of dosimeter measurements Chapter 11 – Photons and neutrons – Charged particles • General characteristics of dosimeters F.A. Attix, Introduction to Radiological Physics and Radiation Dosimetry • Summary Introduction Dosimeter • Radiation dosimetry deals with the determination • A dosimeter can be generally defined as (i.e., by measurement or calculation) of the any device that is capable of providing a absorbed dose or dose rate resulting from the interaction of ionizing radiation with matter reading R that is a measure of the absorbed • Other radiologically relevant quantities are dose Dg deposited in its sensitive volume V exposure, kerma, fluence, dose equivalent, energy by ionizing radiation imparted, etc. can be determined • If the dose is not homogeneous • Measuring one quantity (usually the absorbed dose) another one can be derived through throughout the sensitive calculations based on the defined relationships volume, then R is a measure of mean value Dg Dosimeter Simple dosimeter model • Ordinarily one is not interested in measuring • A dosimeter can generally be considered as the absorbed dose in a dosimeter’s sensitive consisting of a sensitive volume V filled with a volume itself, but rather as a means of medium g, surrounded by a wall (or envelope, determining the dose (or a related quantity) for container, etc.) of another medium w having a another medium in which direct measurements thickness t 0 are not feasible • A simple dosimeter can be
    [Show full text]
  • Absorbed Dose Dose Is a Measure of the Amount of Energy from an Ionizing Radiation Deposited in a Mass of Some Material
    Absorbed Dose Dose is a measure of the amount of energy from an ionizing radiation deposited in a mass of some material. • SI unit used to measure absorbed dose is the gray (Gy). 1J • 1 Gy = kg • Gy can be used for any type of radiation. • Gy does not describe the biological effects of the different radiations. Dosimetric Quantities Quantity Definition New Units Old Units Exposure Charge per unit mass of --- Roentgen air (R) 1 R = 2.58 x 10-4 C/kg Absorbed dose to Energy of radiation R gray Radiation absorbed tissue T from absorbed per unit mass (Gy) dose radiation of type R of tissue T (rad) 1 rad = 100 ergs/g DT,R 1 Gy = 1 joule/kg 1 Gy = 100 rads Equivalent dose to Sum of contributions of Sievert Roentgen tissue T dose to T from (Sv) equivalent man different radiation (rem) HT types, each multiplied by the radiation weighting factor (wR) HT = ΣR wR DT,R Effective Dose Sum of equivalent Sievert rem doses to organs and (Sv) E tissues exposed, each multiplied by the appropriate tissue weighting factor (wT) E = ΣT wT HT 1 Radiological Protection For practical purposes of assessing and regulating the hazards of ionizing radiation to workers and the general population, weighting factors (previously called quality factors, Q) are used. A radiation weighting factor is an estimate of the effectiveness per unit dose of the given radiation relative a to low-LET standard. Weighting factors are dimensionless multiplicative factors used to convert physical dose (Gy) to equivalent dose (Sv) ; i.e., to place biological effects from exposure to different types of radiation on a common scale.
    [Show full text]
  • Ionizing Radiation in Earth's Atmosphere and in Space Near Earth May 2011 6
    Federal Aviation Administration DOT/FAA/AM-11/9 Office of Aerospace Medicine Washington, DC 20591 Ionizing Radiation in Earth’s Atmosphere and in Space Near Earth Wallace Friedberg Kyle Copeland Civil Aerospace Medical Institute Federal Aviation Administration Oklahoma City, OK 73125 May 2011 Final Report OK-11-0024-JAH NOTICE This document is disseminated under the sponsorship of the U.S. Department of Transportation in the interest of information exchange. The United States Government assumes no liability for the contents thereof. ___________ This publication and all Office of Aerospace Medicine technical reports are available in full-text from the Civil Aerospace Medical Institute’s publications Web site: www.faa.gov/library/reports/medical/oamtechreports Technical Report Documentation Page 1. Report No. 2. Government Accession No. 3. Recipient's Catalog No. DOT/FAA/AM-11/9 4. Title and Subtitle 5. Report Date Ionizing Radiation in Earth's Atmosphere and in Space Near Earth May 2011 6. Performing Organization Code 7. Author(s) 8. Performing Organization Report No. Friedberg W, Copeland K 9. Performing Organization Name and Address 10. Work Unit No. (TRAIS) FAA Civil Aerospace Medical Institute P.O. Box 25082 11. Contract or Grant No. Oklahoma City, OK 73125 12. Sponsoring Agency name and Address 13. Type of Report and Period Covered Office of Aerospace Medicine Federal Aviation Administration 800 Independence Ave., S.W. Washington, DC 20591 14. Sponsoring Agency Code 15. Supplemental Notes 16. Abstract The Civil Aerospace Medical Institute of the FAA is charged with identifying health hazards in air travel and in commercial human space travel.
    [Show full text]
  • Radiation Biology: Cell Biology
    Agenda Radiologic Units: • Greys, Sieverts, Coulombs per kg, & What You Need to Becquerel's Know • Conventional Units TODD VAN AUKEN M.ED. RT (R)(MR) • Other Concepts (LET, Q-Factor, Effective Dose, NCRP Report # 116) • Crazy Happenings with Radiation Coulomb per kg or C/kg-Exposure (X) Erythema Dose • A Coulomb (C) is the basic unit of electric charge • Measurement of positive and negative particles created when radiation ionizes atoms in dry air (Radiation intensity in the air) • Unit of Exposure for X-rays and Gamma Rays (Restricted to Photons only) • Used for x-ray equipment calibration (X-ray tube output) • Conventional Unit: Roentgen (R) Air Kerma Gray (Gy)-Absorbed Dose (D) • Kinetic energy is transferred from the primary beam • Amount of energy per unit mass absorbed by an (photons) to the patient (e-) irradiated object • SI quantity that can be used to measure radiation • 1 joule (J) of energy absorbed concentration transferred to a point at the surface of a in 1 g of absorbing material patient’s or radiographer’s body • Absorption of energy may • The energy transfer is called the kinetic energy result in biological damage released in the material or kerma (air kerma) • As the Z# of the object • Dose Area Product (DAP)- sum total of Air Kerma increases the absorbed dose over the exposed area of the patient’s surface (entire increases amount of energy delivered to the patient) • Conventional Unit: RAD (Radiation Absorbed Dose) Linear Energy Transfer Linear Energy Transfer Low LET Low LET High LET High LET LET= Rate at which energy
    [Show full text]
  • Q: What's the Difference Between Roentgen, Rad and Rem Radiation Measurements?
    www.JICReadiness.com Q: What's the Difference Between Roentgen, Rad and Rem Radiation Measurements? A: Since nuclear radiation affects people, we must be able to measure its presence. We also need to relate the amount of radiation received by the body to its physiological effects. Two terms used to relate the amount of radiation received by the body are exposure and dose. When you are exposed to radiation, your body absorbs a dose of radiation. As in most measurement quantities, certain units are used to properly express the measurement. For radiation measurements they are... Roentgen: The roentgen measures the energy produced by gamma radiation in a cubic centimeter of air. It is usually abbreviated with the capital letter "R". A milliroentgen, or "mR", is equal to one one-thousandth of a roentgen. An exposure of 50 roentgens would be written "50 R". Rad: Or, Radiation Absorbed Dose recognizes that different materials that receive the same exposure may not absorb the same amount of energy. A rad measures the amount of radiation energy transferred to some mass of material, typically humans. One roentgen of gamma radiation exposure results in about one rad of absorbed dose. Rem: Or, Roentgen Equivalent Man is a unit that relates the dose of any radiation to the biological effect of that dose. To relate the absorbed dose of specific types of radiation to their biological effect, a "quality factor" must be multiplied by the dose in rad, which then shows the dose in rems. For gamma rays and beta particles, 1 rad of exposure results in 1 rem of dose.
    [Show full text]